whats-new-haiku-5-5 changedmodels/haiku-5-5/whats-new-haiku-5-5
Nearest release: v2.1.309, published 3 hours before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
Lines+1added
Lines−1removed
From line
21
where the diff opens
First seen
8 Oct 2026
this site's first read of the page
Recorded edits6to this page, all time
The whole hunk
from line 21, old and new numbered
/
from line 21
2121| [Manual extended thinking returns an error](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#configure-thinking) | Breaking | Replace `budget_tokens` with adaptive thinking. |
2222| [Sampling parameters can return an error](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#remove-sampling-parameters) | Breaking | Omit `temperature`, `top_p`, and `top_k`. |
2323| [Assistant message prefill returns an error](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#replace-assistant-prefill) | Breaking | End `messages` with a user turn. |
24| [`computer_20250124` returns an error on the Claude API, Claude Models on Google Cloud (Google managed), and Amazon Bedrock](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#computer-use-toolset) | Breaking | Replace it with `computer_toolset_20260801` on the Claude API and Claude Models on Google Cloud (Google managed), or with `computer_20251124` on Amazon Bedrock. |
24| [`computer_20250124` returns an error](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#computer-use-toolset) on the Claude API, Claude Models on Google Cloud (Google managed), and Amazon Bedrock | Breaking | Replace it with `computer_toolset_20260801` on the Claude API and Claude Models on Google Cloud (Google managed), or with `computer_20251124` on Amazon Bedrock. |
2525| [Changing earlier turns invalidates thinking blocks](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#keep-earlier-turns-unchanged) | Breaking | Keep conversations append-only if you send thinking blocks back. |
2626| [Responses can start with thinking blocks](https://platform.claude.com/docs/en/models/haiku-5-5/whats-new-haiku-5-5#responses-can-begin-with-thinking-blocks) | Changed | Select content blocks by `type`, not by position. |
2727| [Thinking text is omitted by default](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide#configure-thinking) | Changed | To receive summarized thinking, set `thinking.display` to `"summarized"`. |
No line in this hunk matches that.